Reciprocating engine



Sept. 5, 1933. c. HAGAN 1,925,754

RECIPROCATING ENGINE FiledJune 18, 1930 INVENTOR CHARLES HAGAN AT TORNEYS Patented Sept. 5, 1933 1,925,754 V RECIPROCATING ENGINE Charles Hagan, Westport, New Zealand' Application June 18, 1930. Serial No. 461,894

1 Claim.

This invention relates to an engine of the reciprocating type and although intended primarily for use as an internal combustion engine, is capable of adaptation to the requirements of steam or other expansive fluid.

It is the object of the present invention to provide a novel and peculiar construction whereby in a single cylinder an efiect may be produced upon the crank-shaft similar to that at present,

cylinder may be directly connected with the I crank-shaft by means of simple connecting-rods contained wholly within the crank-chamber.

By the said construction also the working expansion in the cylinder is more efficiently applied in' rotating the crank-shaft than in the case of engines of the usual piston per cylinder type, while in the simplest form of such construction each impulse resulting from such expansion will be applied to the crank-shaft as a couple, thus producing a balanced effect in all speeds.

In carrying this object into effect the present invention comprises briefly a cylinder containing two working pistons one of which r'ecipro cates within and in the opposite direction to the other, the working expansion occurring in the space between the heads of the two pistons which are thereby forced apart and apply power to the crank-shaft by means of their connected cranks which are arranged at angles of 189 with each other. In additon to this a further impulse may be obtained by an expansion in the space between the head of the outer or sleeve piston and the cover of the cylinder.

In order that the nature of the invention and its construction may be clearly understood, it will now be fully described and explained with reference to the accompanying drawing, in which:

Fig. 1. is a sectional elevation of an engine in accordance with the present invention,

Fig 2. is a sectional elevation along the line 11-11 Fig. Land,

Fig. 3. is asectional elevation along the line 111-111 Fig. 1..

As here shown 1 is acylinder which, according to the present invention is provided with two pistons, via, an outer or sleeve-piston 2 adapted to reciprocate within the bore of the said cylinder, and an inner piston 3 adapted to reciprocate within the said piston 2.

- The inner piston 3 'is connected by means of the customary connecting rod 4; with a crank 5 upon the crank-shaft 6, while the outer or sleeve piston 2 is connected by means of a connectingrod '7 with a crank 8 upon the crank-shaft and arranged at an angle of 180 with the crank 5.

In practice the connecting rod 7 and crank 8 will preferably be duplicated in order that the piston 2inay be connected at two diametrically opposite points with the crank-shaft thus avoiding side-strain upon such piston.

By the said arrangement it will be seen that the pistons 2 and 3 will reciprocate in opposite directions thereby causing the heads of such pistons to move to and from one another, the working expansion occurring in the space between such pistonheads.

In the form here shown by way of illustration the engine is designed to operate as an internal combustion engine of the four-cycle type. For this purpose the cylinder is provided with an inlet-port 9 communicating by means of a longi" tudinal slot 10 in the piston 2 with the interior of the latter, and an outlet or exhaust port 11 similarly communicating with such interior of the piston 2 by means of a longitudinal slot 12, such communications being governed, as necessary for the purpose of producing the functions of the cycle, by valve-gear operated by a layshaft 13 actuated through suitable gearing as 14 from the crank-shaft 6, as customary.

As here shown the said valve-gear comprises a pair of longitudinal slides 15 and 16 arranged face to face with each other at the part of the cylinder at which the said ports occur, the slide 15 being connected by a connecting-rod 1'7 with a crank or eccentric 18 upon the lay shaft 13, while the slide 16 is similarly connected by a connecting-rod 19 with such shaft by a crank or eccentric 20.

The slide 15 is formed at the required points with a pair of through ports 21 and 22 adapted respectively to come into and out of register with the said inlet port 9 and the exhaust-port 11, and similarly the slide 16 is formed with ports 23 and 24 adapted respectively to come into and out of register with the inlet port 9 and the exhaust port 11 and also with the'corresponding ports of the slide15.

Where a working expansion between the two piston-heads only is desire the upper end of the cylinder may be left open or arranged in free communication with the atmosphere.

In cases where so desired however the upper end of the cylinder may be enclosed. gas-tight by .means of a cylinder-cover 25 in order that an additional working expansion may be produced in. the space between such cylinder, cover and the head of the piston'2, or alternatively such space may be employed as a means for con pressing the expansive fluid preparatory to delivering the same to the space between the two piston-heads, as in the case of an engine of the two cycle type.

' As here shown however the space between the cylinder-cover 25 and the head of the piston 2 is arranged to provide a working expansion.

For this purpose the cylinder is provided near its upper end with an additional inlet-port 26 and an additional exhaust-port 2'7 which are governed an exactly similar manner to that of the previously mentioned ports 9 and 11 by the slides 15 and 16, the former of which is formed with a pair of ports 28 and 29 designed to come into and out of register with the ports '26 and 2'7 respectively, while the other slide 16 is formed with ports 30 and 31 designed to come into and out of register with the ports 26 and 27 respectively and with the corresponding ports of the slide 15.

If so desired however poppet-valves, or valves of any other appropriate type, may be substituted for the slides as the necessary means for controlling the admission and exhaust oi the expansive fiuid.

In the case of an engine employing electric ignition and utilizing the space between the head of the piston 2 and the cylinder-cover, as here shown, a spark-plug, as 32 adapted to fire the charge such upper expansion space, may be tapped through the cylinder cover, while for the purpose of firing the charge between the two piston-heads, a second spark-plug 33 may be tapped at an angle through the wall of the cylinder at an intermediate point and the piston 2 formed at the required point with a port 3% adapted to register with the end of such sparkplug when the pistons 2 and 3 are in the firing positions.

Where the space above the piston 2 is not utilized however the plug 33 may obviously be tapped through the head of such piston in. lieu of the arrangement here shown.

In operation, when the heads of the pistons 2 and 3 are moving apart during the induction stroke the ports 21 and 23 will be in register with each other with the inlet-port 9 thereby permitting a charge to be drawn therethrough and through the slot 10 into the space between the said pistonheads. During the next-succeeding stroke, the ports being out of register the charge will be compressed by the movement of the piston-heads towards one another, this continuing until about the end of the stroke when the pistons have assumed the positions here shown. The compressed charge will then be fired, as by means of the spark-plug 33 thereby providing the working expansion which acts equally downward against the head'of the piston 2 thereby causing such pistons, by means of their cranks 8 and 5, to apply their energy to the crank-sliaft as a couple, thus producing a perfectly balanced torque upon such shaft. At the completion of the working stroke the ports 22 and 24 will come into register with each other and with the exhaust-port 11 thereby permitting of the escape of the spent gases through such ports and through the slot 12 as the pistonheads move towards one another in preparation for the next induction stroke.

In the case of an engine of the Diesel type the spark-plug 33 will be replaced by the necessary fuel injection.

In cases where an additional working expansion between the head of the piston 2 and the cylinder-cover is desired, as already mentioned, the ports 28 and 30 may be arranged to come into register with one another and with the inlet port 26 when the exhaust stroke in the space between the pistons is taking place as above described thereby permitting a charge to be drawn into the space above the piston 2 in response to the downward movement of the latter within the cylinder. During the next succeeding lip-stroke of the said piston, the ports being out of register the said charge will be compressed in preparation for firing by means of the spark plug 32 when the piston reaches the top of its stroke thus providing a working expansion upon the top of such piston coinciding Wifli the compression stroke in the space .between the piston-heads. During the next succeeding stroke of the piston 2 coinciding with the working stroke between the pistons, the ports 2! and 31 will be in register with one another and with the exhaust port 29 thereby permitting of the spent gases in the cylinder space above the piston 2 being exhausted by the upward movement of the latter.

In the case of an engine of this construction employing but a single cylinder a working expansion between the two pistons only is considered preferable owing to the fact that, as already explained, such an arrangement provides a balanced torque upon the crank-shaft. 7

In the case of an engine embodying two or more of such cylinder units however the additicnal expansions in the upper portions ofsuch cylinders serve to balance one another thus eliminating the objection which might attach to such an arrangement in the case ofa single cylinder.

It will be seen that by the construction embodying a sleeve-piston within which an inner piston reciprocates both of such pistons may be connected to the crank-shaft by means of simple connecting-rods arranged within the crankchamber.

I claim:

A reciprocating engine comprising a cylinder having one end closed, a sleeve piston slidably arranged in said cylinder with the head of the piston position to form a working chamber between it and the closed end of the cylinder, 2. second piston slidably arranged in the sleeve piston, said pistons being arranged to form a second working chamber within the sleeve piston, said cylinder being formed with a pair of upper inlet and exhaust ports serving the first mentioned working chamber and a pair'of lower inlet and exhaust ports serving the second mentioned working chamber, and said sleeve piston being provided with inlet and exhaust ports cooperating with the last mentioned cylinder ports, an inner slide valve provided with upper inlet and exhaust ports adapted at times to register with the upper inlet and exhaust ports of the cylinder and with a pair of lower inlet and ex haust ports adapted at times to register with the lower inlet and exhaust ports of said cylinder, an outer slide valve provided with upper inlet andexhaust ports adapted at times to register with the upper inlet and exhaust ports of the inner slide valve and the cylinder and with a pair of lower inlet and exhaust ports adapted to register at times with the lower inlet and ex haust ports of the inner valve and cylinder, a crank shaft, means connecting the pistons to the crank shaft so that the pistons move in opposite directions during operation of the engine, a lay shaft driven from the crank shaft and connections between the lay shaft and the slide valves functioning to operate said valves in properly timed relation with respect to the movements of the pistons.

CHARLES HAGAN. 

